CN114575039A

CN114575039A - Non-rebound needle-punched non-woven fabric and preparation method thereof

Info

Publication number: CN114575039A
Application number: CN202210156446.8A
Authority: CN
Inventors: 莫国军; 沈晓林; 葛希
Original assignee: Taizhou Yipu Polymer Material Co ltd
Current assignee: Shangrao Juweixing Technology Co ltd; Taizhou Yipu Polymer Material Co ltd
Priority date: 2022-02-21
Filing date: 2022-02-21
Publication date: 2022-06-03
Anticipated expiration: 2042-02-21
Also published as: CN114575039B

Abstract

The invention discloses a non-rebound needle-punched non-woven fabric and a preparation method thereof, wherein the non-woven fabric comprises the following components: 40-50 parts of PLA/jute fiber composite material, 15-30 parts of PBS, 5-10 parts of modified cotton-flax fiber and 1-2 parts of cross-linking agent. The non-woven fabric adopts PLA/jute fiber composite material, PBS and modified cotton-flax fiber as main materials, wherein the jute fiber and the cotton-flax fiber have stable performance and excellent mechanical property, and the PLA and the PBS are both biodegradable materials, so that the prepared non-woven fabric is high in environmental protection property, easy to degrade, good in toughness and heat resistance, and good in economic benefit and environmental protection benefit.

Description

Non-rebound needle-punched non-woven fabric and preparation method thereof

Technical Field

The invention relates to the technical field of spinning, in particular to a rebound-free needle-punched non-woven fabric and a preparation method thereof.

Background

Nonwoven fabrics are also known as nonwoven fabrics, needle punched cottons, needle punched nonwoven fabrics, and the like. Nonwoven fabrics are made of oriented or random fibers. It is called a cloth because of its appearance and certain properties. The non-woven fabric has the characteristics of moisture resistance, air permeability, flexibility, light weight, no combustion supporting, easy decomposition, no toxicity or irritation, rich color, low price, recycling and the like. The plastic is mainly produced by adopting plastic particles as raw materials through a continuous one-step method of high-temperature melting, spinning, laying a line and hot-pressing coiling.

However, the non-woven fabric preparation materials such as PET fibers provided in the prior art have poor degradability, high recovery cost and great environmental pollution, and cannot meet the concept of green environmental development. Moreover, the existing non-woven fabric material has poor stability, and particularly natural fibers are easy to rebound after long-time use, so that the non-woven fabric structure is damaged.

For example, the application number is [ CN202110530103.9 ], the high permeability non-woven fabric doped with natural fibers is formed by alternately laminating and needling a plurality of single-layer hydrophilic non-woven fabrics and a plurality of single-layer hydrophobic non-woven fabrics; the single-layer hydrophilic non-woven fabric comprises, by weight, 50-60 parts of hydrophilic modified cellulose fibers, 300 parts of impurity removal impregnation liquid and 50-60 parts of bleaching liquid. The non-woven fabric prepared from the cellulose fibers has excellent air permeability and moisture absorption and better fit with the skin of a human body.

However, the non-woven fabric mainly comprises a preparation material such as hydrophilic modified cellulose fibers, and although the non-woven fabric has excellent performance, the non-woven fabric prepared from the hydrophilic modified cellulose fibers has poor mechanical properties and high manufacturing cost, and the pure fibers have poor stability and may have the problems of rebound and fluffiness after long-term use.

Disclosure of Invention

In order to solve the problems, the invention provides a non-rebound needle-punched non-woven fabric and a preparation method thereof, the non-woven fabric is prepared by adopting PLA/jute fiber composite material, PBS and modified cotton-flax fiber as main materials, the PLA and the PBS fiber are hot-pressed at high temperature and then the surfaces of the PLA and the PBS fiber are melted, the jute fiber and the cotton-flax fiber can be bonded, the stability of the non-woven fabric is improved on the premise of ensuring the air permeability of the non-woven fabric, and the phenomena of rebound, fluffiness and the like after long-term use are avoided.

In order to achieve the purpose, the invention is realized by the following technical scheme: on one hand, the invention provides a non-rebound needle-punched non-woven fabric which comprises the following components in parts by weight: 40-50 parts of PLA/jute fiber composite material, 15-30 parts of PBS, 5-10 parts of modified cotton-flax fiber and 1-2 parts of cross-linking agent.

The non-woven fabric prepared by adopting PLA as a substrate material has excellent air permeability, acid and alkali resistance and mechanical properties. However, it is inferior in strong heat resistance and unstable in heat. Therefore, the jute fiber and the PLA are compounded to prepare the composite material.

Preferably, the PLA composite is a PLA/jute fiber composite.

Preferably, the preparation method of the PLA/jute fiber composite material comprises the following steps: firstly, placing maleic anhydride grafted polylactic acid in a vacuum drying oven at 60 ℃ for drying for 24h, placing the dried maleic anhydride grafted polylactic acid in a plasticator, banburying for 1min at 170 ℃ at a rotating speed of 30min-1, then adding the modified jute fiber in the plasticator, and banburying for 10min to obtain the PLA/jute fiber composite material.

In recent years, human beings face serious problems of environmental pollution and shortage of non-renewable resources. The application range of plastic products is wider and wider, however, the production of the traditional plastic needs non-renewable petroleum resources as raw materials, and the waste treatment causes serious pollution to the environment. Thus, polylactic acid (PLA), a fully biodegradable non-petroleum based material, is currently a focus of research.

However, polylactic acid has high brittleness, poor toughness, poor impact resistance and poor thermal stability. In order to improve various properties of polylactic acid, jute fiber is adopted as a reinforcing component to reinforce PLA. The jute fiber is used as natural plant fiber and has the characteristics of good rigidity, good toughness, large elongation at break, good weather resistance, good low-temperature performance, low price, heat insulation, good dimensional stability and the like. The jute fiber used as the filler reinforced polymer material can not only reinforce the polylactic acid of the matrix material, but also play a role of a crystallization nucleating agent, and can effectively improve the thermal stability of the matrix material.

In the composite material provided by the invention, when the jute fiber content is high, the polylactic acid content in the composite material is low, so that the polylactic acid cannot fully wrap the fiber, the bonding effect between the polymer and the fiber is weakened, and the mechanical property of the composite material is further influenced. Polylactic acid can not be fully mixed and wrapped with fiber, and serious poor glue phenomenon can occur. Therefore, the content of polylactic acid is not preferably more than 30%.

Preferably, the mass ratio of the maleic anhydride grafted polylactic acid to the modified jute fiber is 7: (2-3).

In addition, polylactic acid is a hydrophobic substance, and jute fibers have hydrophilicity and poor compatibility with polylactic acid. Therefore, the invention is to perform chemical modification on the surface of the jute fiber or add an interface modifier to improve the bonding degree between the polylactic acid and the jute fiber.

In order to improve the interfacial compatibility of the polylactic acid/jute fiber composite material, the invention uses silane coupling agent KH550 to carry out surface treatment on jute fiber.

Preferably, the modification treatment process of the jute fiber is as follows: firstly, taking 95% ethanol by volume fraction, adding a small amount of acetic acid while stirring to adjust the pH value to 4, then adding a silane coupling agent KH550 to prepare a silane coupling agent solution with the mass fraction of (0.5-1)%, standing for a moment, then soaking the jute fibers after alkali treatment into the prepared silane coupling agent solution, taking out after 1h, washing with ethanol, finally placing the jute fibers into a blast drying oven, and drying for 6h at 80 ℃ for later use.

According to the invention, the surface of the jute fiber is subjected to silane treatment, so that the adhesion between the fiber and the polylactic acid matrix can be enhanced. The main component of jute fiber is cellulose, which contains a large amount of hydroxyl groups having hydrophilicity, and polylactic acid resin has hydrophobicity. The improvement of the interface compatibility between the two is the key to improve each performance of the composite material.

In the present invention, the reaction mechanism of the silane-treated jute fiber is as follows: firstly, the silane coupling agent is hydrolyzed in ethanol solution containing water to generate silanol groups (Si-OH). Then the silanol group reacts with the hydroxyl on the surface of the Jute fiber to generate a covalent bond (Jute-O-Si). The remaining silanol groups form hydrogen bonds or polymerize with adjacent silanol groups. Finally, the silane molecules attached to the jute fiber are bonded to the polylactic acid matrix by chemical bonds or van der waals forces.

And the amino and hydroxyl in the hydrolyzed silane coupling agent KH550 respectively react with polylactic acid and jute fiber, so that the interface compatibility is improved. And with the increase of the concentration of the silane coupling agent, the silane functional group connected to the jute fiber is subjected to self polymerization to generate a net structure, a certain intermolecular interlocking effect is formed, and the interfacial adhesive force between the fiber and the polylactic acid is increased. The improvement of the interface adhesiveness strengthens the stress transfer effect, so that the tensile strength of the composite material is increased, and the mechanical property of the material is improved.

After the jute fiber is treated by silane, the interaction between the jute fiber and a polylactic acid matrix is enhanced, the regular arrangement of polylactic acid molecular chains is destroyed, the crystallization capacity is reduced, and the crystallinity is reduced; the dimer or oligomer generated by the silane functional group undergoing self-polymerization can act as a nucleating agent, so that the crystallization capacity is improved; the dimer or oligomer generated by the silane functional group reaction plays a role in lubrication, so that the PLA chain segment is easy to move, and the crystallization capacity is improved.

However, the jute fiber has a large amount of hemicellulose, lignin, wax and other impurities on the surface, the impurities are wrapped on the surface of the jute fiber, the infiltration of PLA to the cellulose is prevented, and meanwhile, the contact between amino and hydroxyl in the silane coupling agent KH550 and the jute fiber is not sufficient, so that the interfacial adhesion between the PLA substrate material and the jute fiber cannot be improved.

Therefore, the present invention alkali-treats jute fibers before silane-treating them.

Preferably, the alkali treatment process of the jute fiber is as follows: soaking jute fiber in 5 wt% sodium hydroxide solution for 3 hr, taking out, washing with distilled water, drying in air-blast drying oven at 80 deg.C to constant weight, and keeping.

Firstly, the alkali treatment can wash away impurities such as hemicellulose, lignin, wax and the like on the surface of jute fiber, so that the jute becomes soft and loose. The alkali treatment increases the surface roughness of the jute fiber, so that the mechanical interlocking action between the fiber and the polymer matrix is enhanced, the bonding action between the polylactic acid and the jute fiber is enhanced to a certain degree, and the amino and hydroxyl in the silane coupling agent KH550 are easier to contact with the jute fiber.

Secondly, the jute fiber treated by the alkali solution can enhance the tensile strength and the impact strength of the composite material. Fibrilia belongs to natural organic cellulose fiber, and one ring in a repeating unit of the fibrilia contains 3 hydroxyl groups. In the alkali treatment process, alkali metal ions or alkali molecules can be combined with hydroxyl groups, so that hydrogen bonds in the fibers are reduced and intermolecular forces are weakened; the alkali treatment removes part of hemicellulose and pectin in jute fibers, so that the areas between fibrils with optimal rotation angles become looser and softer and the bonding degree of cellulose microfibrils is weakened; after alkali treatment, the crystallinity index of jute fiber is reduced, and partial crystalline regions in the fiber are converted into an amorphous structure. The factors can increase the spacing between cellulose macromolecules and make the fibers soft and loose, so that when the fibers bear tensile stress, the fibrils can be better unscrewed, deformed and rearranged along the stress direction, and the load can be better distributed among the fibrils, thereby improving the tensile load bearing capacity of the fibers. On the other hand, the alkali treatment can cause the fiber to undergo irreversible swelling, the fiber wall thickness is increased, the cross section shape is changed, the original oval shape is changed to a round shape, and the inner cavity of the fiber is enlarged, so that the rigidity and the strength of the fiber and the composite material thereof are improved to a certain extent.

Finally, analysis of the energy absorption mechanism at impact fracture of the composite material shows that the impact energy is mainly dispersed by fiber pull-out and interfacial failure. The alkali treatment can improve the swelling toughness of the fiber and enlarge the middle pore space, so that in the process of pulling out the fiber, the friction motion between the fiber and the matrix is enhanced and the deformation of the matrix is increased, and more energy is consumed. Meanwhile, the enlargement of the fiber middle lumen makes it easy for the PLA resin to be immersed in the cavities of the ducts, sieve tubes, parenchyma cells, etc. of the jute fiber bundle, which may block a part of the passage of water into the jute fiber, increase the hydrophobicity of the jute fiber, thereby increasing the bonding strength of the interface between the jute fiber and the PLA matrix. In addition, after alkali treatment, the crystallinity index of the jute fiber is reduced, a part of crystalline regions are converted into amorphous structures, the macromolecular chains of the fiber in the amorphous regions are disordered and have more gaps and holes, so that the effective contact area of the fiber and the PLA matrix is increased, and the bonding strength of the interface between the jute fiber and the brittle PLA resin matrix is effectively improved to a certain extent. In addition, jute fibers have an optimum fibril helix angle in natural fibers, and a large amount of work to break is also consumed by relative displacement, unwinding and rearrangement of fibrils caused by relaxation of the regions between fibrils after alkali treatment.

In order to further improve the interface compatibility between the jute fiber and the polylactic acid, the invention also carries out modification treatment on the polylactic acid.

Preferably, the preparation method of the maleic anhydride grafted polylactic acid is as follows: grinding dicumyl peroxide and maleic anhydride into powder, mixing dicumyl peroxide powder, maleic anhydride powder and dried polylactic resin uniformly, adding into a plasticator, wherein the temperature of the plasticator is 170 ℃, and the rotating speed is 30min^-1And banburying for 10min to obtain the maleic anhydride grafted polylactic acid.

Preferably, the mass ratio of dicumyl peroxide to maleic anhydride to polylactic acid is 1: 4: 200.

the acid anhydride group on the maleic anhydride grafted polylactic acid (MAPLA) reacts with the hydroxyl group of the jute fiber to form ester on the surface of the jute fiber, so that the interface compatibility between the jute fiber and the polylactic acid is improved, the stress can be effectively transferred to the filler jute fiber from a polylactic acid matrix, and the composite material can bear larger stress and the tensile strength is increased along with the stress. And the maleic anhydride grafted polylactic acid is added into the system, after banburying, the jute fiber is broken in the middle, the surface of the fiber is rough, and the polylactic acid is adhered to the surface of the fiber, so that the connectivity between the polylactic acid and the jute fiber is enhanced, and the mechanical property of the material is improved.

The cotton and hemp fibers are added to prepare the non-woven fabric, are natural plant fibers, can be completely degraded after being discarded, and are excellent in environmental protection.

The cotton and flax are textiles prepared by blending cotton fibers and flax fibers as raw materials, wherein cotton and flax are grown from temperate plants, are respectively picked from seed parts of cotton and pyrene flax, are dried in the sun, are threshed by a machine, are decomposed into the seed parts and the cotton and flax parts, and are rolled and pressed by the machine to be blended into threads to prepare the product. Due to the hollow skin-core-like structure of the flax fibers and the cotton fibers, the inner plate has rich pore structures. However, the effect of dyeing is not so good, the dye uptake is not high, the washing fastness is not strong, and the processability is poor due to the problems of the characteristics of the cotton and linen fibers.

Due to the existence of polar hydroxyl in molecules, hydrogen bonds are easily formed between cellulose macromolecules of the cotton-flax fibers, so that the cotton-flax fibers are unevenly connected when being combined with PLA and PBS resin, the interfaces of the cotton-flax fibers and the PLA cannot be well contacted, stress cannot be effectively transferred at the interfaces, the cohesiveness between the resin and the cotton-flax fibers is poor, the impact strength and the tensile strength of the prepared non-woven fabric can be remarkably reduced, and the comprehensive performance of the composite material is influenced.

Preferably, the preparation method of the modified cotton-flax fiber comprises the following steps: soaking the cotton and hemp fibers to be treated in clear water for 5min, fishing out the cotton and hemp fibers, soaking the cotton and hemp fibers in a 4% sodium hydroxide solution for 6-8min, fishing out the cotton and hemp fibers, cleaning the cotton and hemp fibers in clear water for 10-15min, fishing out the cotton and hemp fibers, and drying the cotton and hemp fibers in a constant temperature drying oven for 2-3h for later use.

Therefore, the alkali treatment is carried out on the cotton and linen fibers, the sodium hydroxide solution has better swelling effect, the swelling effect is enhanced along with the prolonging of the soaking time, the cell walls of the cotton and linen fibers become loose, the cellulose partial crystallization area is swelled and even destroyed, and more free hydroxyl groups are exposed, so that the resin material is easy to permeate into the fiber tissue structure and attached to the surface or the inside of the cotton and linen fibers, and the mechanical property and the processing property of the cotton and linen fibers are further improved.

On the other hand, the invention also provides a preparation method of the non-rebound needle-punched non-woven fabric, which comprises the following steps:

s1, drying: drying the PLA/jute fiber composite material, the PBS and the modified cotton-flax fiber until the water content is less than 35ppm for later use;

s2, melting: mixing the PLA/jute fiber composite material dried in the S1, PBS, modified bamboo fiber and modified cotton-hemp fiber, feeding the mixture into melting equipment for melting, adding a cross-linking agent after melting, and uniformly stirring to obtain a melt;

s3, wire drawing: drawing the melt obtained in the step S2 through a spinning box, cooling tows through side blowing while drawing, scattering and paving the tows on a transmission net curtain;

s4, needling: needling the net-shaped non-woven fabric laid in the step S3 by a needle machine to obtain a needled non-woven fabric;

s5, hot pressing: and (5) carrying out hot press molding on the needled non-woven fabric obtained in the step (S4) by using a flat vulcanizing machine to obtain a finished product non-rebound needled non-woven fabric.

Compared with the prior art, the invention has the following beneficial effects:

1. the non-woven fabric provided by the invention adopts PLA/jute fiber composite material, PBS and modified cotton-flax fiber as main materials, wherein the jute fiber and the cotton-flax fiber have stable performance and excellent mechanical performance, and the PLA and the PBS are biodegradable materials, so that the prepared non-woven fabric is high in environmental protection property, easy to degrade, good in toughness and heat resistance, and good in economic benefit and environmental protection benefit.

2. According to the non-rebound needle-punched non-woven fabric provided by the invention, in the process of preparing the non-woven fabric, the non-woven fabric main body is obtained through needle punching, and finally the surfaces of PLA and PBS are melted through hot pressing to form a complete bonding system, so that the plant fibers are bonded, the function of a hot-melt adhesive is realized, and the problems of rebound fluffiness and the like of the non-woven fabric after long-time use can be avoided.

Drawings

Fig. 1 is a flow chart of a method for manufacturing a non-rebound needle-punched non-woven fabric in the embodiment of the invention.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention and the technical solutions in the prior art, the following will describe the specific embodiments of the present invention with reference to the accompanying drawings.

It is obvious that the drawings in the following description are only some examples of the invention, and it is obvious to a person skilled in the art that other drawings and other embodiments can be obtained from these drawings without inventive effort, and the invention is not limited to this example.

The specific embodiment of the invention is as follows:

example 1

A non-rebound needle-punched non-woven fabric comprises the following components in parts by weight: 40 parts of PLA/jute fiber composite material, 15 parts of PBS, 5 parts of modified cotton-flax fiber and 1 part of hydrogen peroxide diisopropylbenzene.

The PLA composite material is a PLA/jute fiber composite material. The preparation method of the PLA/jute fiber composite material comprises the following steps: firstly, maleic anhydride grafted polylactic acid is placed in a vacuum drying oven at 60 ℃ for drying for 24 hours, and then is placed in a plasticator after being dried, and the rotating speed is 30min at 170 DEG C^-1Banburying for 1min, adding the modified jute fiber into a plasticator, and banburying for 10min to obtain the PLA/jute fiber composite material. Wherein the mass ratio of the maleic anhydride grafted polylactic acid to the modified jute fiber is 7: 2.

the modification treatment process of the jute fiber comprises the following steps: firstly, taking 95% ethanol by volume fraction, adding a small amount of acetic acid while stirring to adjust the pH value to 4, then adding a silane coupling agent KH550 to prepare a silane coupling agent solution with the mass fraction of 0.5%, standing for a moment, then soaking the jute fibers subjected to alkali treatment into the prepared silane coupling agent solution, taking out after 1 hour, washing with ethanol, finally, putting the jute fibers into a blast drying oven, and drying for 6 hours at 80 ℃ for later use.

The alkali treatment process of the jute fiber comprises the following steps: soaking jute fiber in 5 wt% sodium hydroxide solution for 3 hr, taking out, washing with distilled water, drying in air-blast drying oven at 80 deg.C to constant weight, and keeping.

The preparation method of the maleic anhydride grafted polylactic acid comprises the following steps: grinding dicumyl peroxide and maleic anhydride into powder, mixing dicumyl peroxide powder, maleic anhydride powder and dried polylactic resin uniformly, adding into a plasticator, wherein the temperature of the plasticator is 170 ℃, and the rotating speed is 30min^-1And banburying for 10min to obtain the maleic anhydride grafted polylactic acid. Wherein the mass ratio of dicumyl peroxide to maleic anhydride to polylactic acid is 1: 4: 200.

the preparation method of the modified cotton-flax fiber comprises the following steps: soaking the cotton and hemp fibers to be treated in clear water for 5min, fishing out the cotton and hemp fibers, soaking the cotton and hemp fibers in a 4% sodium hydroxide solution for 6min, fishing out the cotton and hemp fibers, cleaning the cotton and hemp fibers in the clear water for 10min, fishing out the cotton and hemp fibers, and drying the cotton and hemp fibers in a constant temperature drying oven for 2h for later use.

The preparation method of the non-rebound needle-punched non-woven fabric is carried out according to the conditions corresponding to the components, and comprises the following steps:

s2, melting: mixing the PLA/jute fiber composite material dried in the S1, PBS, modified bamboo fiber and modified cotton-hemp fiber, feeding the mixture into melting equipment for melting, adding hydrogen peroxide diisopropylbenzene after melting, and uniformly stirring to obtain a melt;

s3, wire drawing: drawing the melt obtained in the step S2 through a spinning box, cooling tows through side blowing while drawing, scattering, and paving on a transmission net curtain;

s5, hot pressing: and (4) carrying out hot press molding on the needled non-woven fabric obtained in the step (S4) by using a flat vulcanizing machine to obtain a finished product of the non-rebound needled non-woven fabric.

Example 2

A non-rebound needle-punched non-woven fabric comprises the following components in parts by weight: 45 parts of PLA/jute fiber composite material, 23 parts of PBS, 7 parts of modified cotton-flax fiber and 1.5 parts of hydrogen peroxide diisopropylbenzene.

The PLA composite material is a PLA/jute fiber composite material. The preparation method of the PLA/jute fiber composite material comprises the following steps: firstly, maleic anhydride grafted polylactic acid is placed in a vacuum drying oven at 60 ℃ for drying for 24 hours, and then is placed in a plasticator after being dried, and the rotating speed is 30min at 170 DEG C^-1Banburying for 1min, adding the modified jute fiber into a plasticator, and banburying for 10min to obtain the PLA/jute fiber composite material. Wherein the mass ratio of the maleic anhydride grafted polylactic acid to the modified jute fiber is 7: 2.5.

the modification treatment process of the jute fiber comprises the following steps: firstly, taking 95% ethanol by volume fraction, adding a small amount of acetic acid while stirring to adjust the pH value to 4, then adding a silane coupling agent KH550 to prepare a silane coupling agent solution with the mass fraction of 0.8%, standing for a moment, then soaking the jute fibers subjected to alkali treatment into the prepared silane coupling agent solution, taking out after 1 hour, washing with ethanol, finally, putting the jute fibers into a blast drying oven, and drying for 6 hours at 80 ℃ for later use.

The preparation method of the maleic anhydride grafted polylactic acid comprises the following steps: grinding dicumyl peroxide and maleic anhydride into powder, uniformly mixing the dicumyl peroxide powder, the maleic anhydride powder and the dried polylactic resin, and adding the mixture into a plasticatorThe temperature is 170 ℃, and the rotating speed is 30min^-1And banburying for 10min to obtain the maleic anhydride grafted polylactic acid. Wherein the mass ratio of dicumyl peroxide to maleic anhydride to polylactic acid is 1: 4: 200.

the preparation method of the modified cotton-flax fiber comprises the following steps: soaking the cotton and hemp fibers to be treated in clear water for 5min, fishing out the cotton and hemp fibers after the soaking for 7min, fishing out the cotton and hemp fibers after the soaking, putting the cotton and hemp fibers in clear water for cleaning for 13min, fishing out the cotton and hemp fibers after the soaking, and putting the cotton and hemp fibers in a constant temperature drying oven for drying for 2.5h for later use.

Example 3

A non-rebound needle-punched non-woven fabric comprises the following components in parts by weight: 50 parts of PLA/jute fiber composite material, 30 parts of PBS, 10 parts of modified cotton-flax fiber and 2 parts of hydrogen peroxide diisopropylbenzene.

The PLA composite material is a PLA/jute fiber composite material. The preparation method of the PLA/jute fiber composite material comprises the following steps: firstly, maleic anhydride grafted polylactic acid is placed in a vacuum drying oven at 60 ℃ for drying for 24 hours, and then is placed in a plasticator after being dried, and the rotating speed is 30 at 170 DEGmin^-1Banburying for 1min, adding the modified jute fiber into a plasticator, and banburying for 10min to obtain the PLA/jute fiber composite material. Wherein the mass ratio of the maleic anhydride grafted polylactic acid to the modified jute fiber is 7: 3.

the modification treatment process of the jute fiber comprises the following steps: firstly, taking 95% ethanol by volume fraction, adding a small amount of acetic acid while stirring to adjust the pH value to 4, then adding a silane coupling agent KH550 to prepare a silane coupling agent solution with the mass fraction of 1%, standing for a moment, then soaking the jute fibers subjected to alkali treatment into the prepared silane coupling agent solution, taking out after 1h, washing with ethanol, finally placing the jute fibers into a blast drying oven, and drying for 6h at 80 ℃ for later use.

The preparation method of the maleic anhydride grafted polylactic acid comprises the following steps: grinding dicumyl peroxide and maleic anhydride into powder, mixing dicumyl peroxide powder, maleic anhydride powder and dried polylactic resin uniformly, and adding into a plasticator at 170 ℃ for 30min^-1And banburying for 10min to obtain the maleic anhydride grafted polylactic acid. Wherein the mass ratio of dicumyl peroxide to maleic anhydride to polylactic acid is 1: 4: 200.

the preparation method of the modified cotton-flax fiber comprises the following steps: soaking the cotton and hemp fibers to be treated in clear water for 5min, fishing out the cotton and hemp fibers, soaking the cotton and hemp fibers in a 4% sodium hydroxide solution for 8min, fishing out the cotton and hemp fibers, cleaning the cotton and hemp fibers in the clear water for 15min, fishing out the cotton and hemp fibers, and drying the cotton and hemp fibers in a constant temperature drying oven for 3h for later use.

s4, needling: needling the net-shaped non-woven fabric laid in the step S3 by using a needling machine to obtain a needled non-woven fabric;

Comparative example 1

On the basis of example 2, conventional PLA was used instead of the PLA/jute fiber composite as the condition of comparative example 1, and the nonwoven fabric of comparative example 1 was prepared.

Comparative example 2

On the basis of example 2, conventional cotton and hemp fibers were used in place of the modified cotton and hemp fibers as the conditions of comparative example 2, and the nonwoven fabric of comparative example 2 was prepared.

Comparative example 3

On the basis of example 2, the hot pressing of step S5 was omitted in the preparation of the nonwoven fabric, and the finished nonwoven fabric was obtained after completion of the needle punching of S4, which was used as the conditions of comparative example 3, and the nonwoven fabric of comparative example 3 was prepared.

Test example 1

Mechanical property tests were performed on the nonwoven fabrics obtained in examples 1 to 3 and comparative examples 1 to 2 according to the protocol described in GB/T17639-2008 geosynthetic filament spunbond needle-punched nonwoven geotextile, and the test results are shown in table 1 below, in which the nominal breaking strength was set to 50kN/m, the elongation in the transverse and longitudinal directions in the table also became the elongation in the transverse and longitudinal directions at that strength, and when the strength in the transverse and longitudinal directions was less than 50kN/m, the elongation at break was recorded.

TABLE 1 results of mechanical Properties test of nonwoven fabrics obtained in examples 1 to 3 and comparative examples 1 to 2

Item	Transverse and longitudinal fracture strength kN/m	Transverse and longitudinal elongation (%)	CBR bursting strength kN	Transverse and longitudinal tearing strength kN
					Example 1	62.5	49.5	12.2	2.5
Example 2	61.8	48.4	12.1	2.5
					Example 3	61.3	47.1	12.1	2.4
Comparative example 1	38.9	22.5	4.7	0.5
					Comparative example 2	58.3	45.1	10.1	2.0

As can be seen from the test results in Table 1, the breaking strength, elongation and strength of the nonwoven fabrics prepared in examples 1 to 3 were all improved more than those of comparative example 1. This is probably because in examples 1-3, in the PLA/jute fiber composites, the jute fibers were first subjected to an alkali treatment, which could wash away impurities such as hemicellulose, lignin, and wax from the surface of the jute fibers, and thus the jute fibers became soft and loose. The alkali treatment increases the surface roughness of the jute fiber, so that the mechanical interlocking action between the fiber and the polymer matrix is enhanced, the bonding action between the polylactic acid and the jute fiber is enhanced to a certain degree, and the amino and hydroxyl in the silane coupling agent KH550 are easier to contact with the jute fiber. And then the surface of the jute fiber is subjected to silane treatment, so that the adhesion between the jute fiber and a polylactic acid matrix can be enhanced. And finally, grafting the polylactic acid with maleic anhydride. Further improving the mechanical property of the PLA/jute fiber composite material, and greatly improving the mechanical property of the prepared non-woven fabric.

Meanwhile, the breaking strength, the elongation and the strength of the non-woven fabrics prepared in the examples 1 to 3 are slightly improved compared with those of the non-woven fabric prepared in the comparative example 2. This is probably because, in comparative example 2, the cotton and hemp fibers were not modified, but in examples 1 to 3, the sodium hydroxide solution had a better swelling effect, and as the soaking time was prolonged, the swelling effect was enhanced, the cell walls of the cotton and hemp fibers became loose, and the crystalline regions of the cellulose were swollen or even destroyed, exposing more free hydroxyl groups, so that the resin material was easily penetrated into the fibrous tissue structure and adhered to the surface or inside of the cotton and hemp fibers, and further improving the mechanical properties of the material.

Test example 2

And (3) aging resistance testing: the samples of the nonwoven fabrics produced in examples 1-3 and comparative examples 1-2 were subjected to irradiation treatment with reference to the relative ultraviolet spectral irradiance in the solar ultraviolet region of a type 1A lamp in GB/T16422.3 (method a), and then mechanical property measurements were again carried out according to the protocol carried on GB/T17639-2008 geosynthetic filament spunbond needle-punched nonwoven geotextile, with the test results shown in table 2.

TABLE 2 mechanical property test results of non-woven fabrics obtained in examples 1 to 3 and comparative examples 1 to 2 after light irradiation

Item	Transverse and longitudinal fracture strength kN/m	Transverse and longitudinal elongation (%)	CBR bursting strength kN	Transverse and longitudinal tearing strength kN
					Example 1	61.9	49.5	11.9	2.5
Example 2	61.8	48.1	11.9	2.5
					Example 3	61.5	47.0	11.8	2.4
Comparative example 1	35.6	21.3	4.1	0.4
					Comparative example 2	57.6	44.6	9.5	1.6

From the results in Table 2, it is understood that the mechanical properties of the nonwoven fabrics prepared in examples 1 to 3 were almost unchanged after the light irradiation treatment, and the nonwoven fabrics prepared in examples 1 to 3 were strong in stability and excellent in aging resistance.

The mechanical properties of the nonwoven fabric prepared in comparative example 1 were greatly reduced by the light treatment, which is probably due to the reinforcing treatment of PLA using jute fibers as the reinforcing component in examples 1 to 3. The jute fiber used as filler to reinforce the high polymer material can not only reinforce the polylactic acid of the matrix material, but also play a role of a crystallization nucleating agent, thereby improving the thermal stability of the PLA matrix material.

The mechanical properties of the nonwoven prepared in comparative example 2 were slightly reduced after the illumination treatment. This is probably because the cotton-flax fibers adopted in comparative example 2 are not treated with alkali, and the cotton-flax fibers are liable to form hydrogen bonds between cellulose macromolecules due to the existence of polar hydroxyl groups in molecules, so that the connection of the plant fibers is not uniform when the plant fibers are combined with the PLA and PBS resins, the interfaces of the plant fibers and the PLA and the PBS resins cannot be well contacted, and the stress cannot be effectively transferred at the interfaces, so that the cohesiveness between the resins and the plant fibers is poor, the thermal stability is poor, and the plant fibers are not uniformly dispersed in the resin system of the PLA and the PBS after the illumination treatment, so that the mechanical properties of the material are reduced.

Test example 3

The nonwoven fabrics prepared in examples 1-3 and comparative example 3 were recorded for long term observation and were recorded for fluffiness and rebound.

TABLE 3 fluffing and bouncing phenomena of the nonwovens obtained in examples 1-3 and comparative example 3

Test specimen	10 days	20 days	30 days	40 days
					Example 1	Surface integrity	Surface integrity	Surface integrity	Surface integrity
Example 2	Surface integrity	Surface integrity	Surface integrity	Surface integrity
					Example 3	Surface integrity	Surface integrity	Surface integrity	Surface integrity
Comparative example 3	Surface integrity	Surface integrity	Surface fluffiness	Surface fluffiness

From the results in Table 3, it is clear that the nonwoven fabrics prepared in examples 1 to 3 are excellent in stability and free from the occurrence of fluffiness, rebound, and the like. The non-woven fabric prepared in the comparative example 3 is not subjected to hot pressing, and the fluffy phenomenon appears on the surface of the non-woven fabric prepared in the comparative example, which indicates that part of jute fibers or cotton-flax fibers are separated from the resin system and the overall stability of the system is poor.

The above-described aspects may be implemented individually or in various combinations, and such variations are within the scope of the present invention.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the specific embodiments of the invention be limited to these descriptions. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.

Claims

1. The non-rebound needle-punched non-woven fabric is characterized by comprising the following components in parts by weight: 40-50 parts of PLA/jute fiber composite material, 15-30 parts of PBS, 5-10 parts of modified cotton-flax fiber and 1-2 parts of cross-linking agent.

2. The non-elastic non-woven fabric as claimed in claim 1, wherein the PLA composite material is a PLA/jute fiber composite material.

3. The non-elastic non-woven fabric according to claim 2, wherein the PLA/jute fiber composite is prepared by the following method: firstly, maleic anhydride grafted polylactic acid is placed in a vacuum drying oven at 60 ℃ for drying for 24 hours, and then is placed in a plasticator after being dried, and the rotating speed is 30min at 170 DEG C^-1Banburying for 1min, adding the modified jute fiber into a plasticator, and banburying for 10min to obtain the PLA/jute fiber composite material.

4. The non-bouncing needling non-woven fabric according to claim 3, wherein the mass ratio of the maleic anhydride grafted polylactic acid to the modified jute fiber is 7: (2-3).

5. The non-elastic needle-punched non-woven fabric as claimed in claim 3, wherein the jute fiber is modified by the following process: firstly, taking 95% ethanol by volume fraction, adding a small amount of acetic acid while stirring to adjust the pH value to 4, then adding a silane coupling agent KH550 to prepare a silane coupling agent solution with the mass fraction of (0.5-1)%, standing for a moment, then soaking the jute fibers after alkali treatment into the prepared silane coupling agent solution, taking out after 1h, washing with ethanol, finally placing the jute fibers into a blast drying oven, and drying for 6h at 80 ℃ for later use.

6. The non-elastic needle punched non-woven fabric as claimed in claim 5, wherein the alkali treatment process of the jute fiber is as follows: soaking jute fiber in 5 wt% sodium hydroxide solution for 3 hr, taking out, washing with distilled water, drying in air-blast drying oven at 80 deg.C to constant weight, and keeping.

7. The non-rebound needle punched non-woven fabric as claimed in claim 3, wherein the maleic anhydride grafted polylactic acid is prepared by the following method: grinding dicumyl peroxide and maleic anhydride into powder, mixing dicumyl peroxide powder, maleic anhydride powder and dried polylactic resin uniformly, adding into a plasticator, wherein the temperature of the plasticator is 170 ℃, and the rotating speed is 30min^-1And banburying for 10min to obtain the maleic anhydride grafted polylactic acid.

8. The non-rebound needle punched non-woven fabric as claimed in claim 7, wherein the mass ratio of dicumyl peroxide, maleic anhydride and polylactic acid is 1: 4: 200.

9. the non-rebound needle punched non-woven fabric as set forth in claim 1, wherein the modified cotton and hemp fiber is prepared by the following method: soaking the cotton and hemp fibers to be treated in clear water for 5min, fishing out the cotton and hemp fibers, soaking the cotton and hemp fibers in a 4% sodium hydroxide solution for 6-8min, fishing out the cotton and hemp fibers, cleaning the cotton and hemp fibers in clear water for 10-15min, fishing out the cotton and hemp fibers, and drying the cotton and hemp fibers in a constant temperature drying oven for 2-3h for later use.

10. A method for preparing a non-resilient needle-punched non-woven fabric as claimed in any one of claims 1 to 9, comprising the steps of: